tasks/easy/password_validator.py

"""
SecureCodeEnv Task: Password Validator
Difficulty: Easy
CWE Targets: CWE-916 (Weak Password Hashing), CWE-521 (Weak Password Requirements)

Agent must write a function that:
1. Validates password strength (length, complexity)
2. Hashes using bcrypt — NOT MD5/SHA1/SHA256
3. Returns False for weak passwords
"""

TASK = {
    "id": "easy_password_validator",
    "difficulty": "easy",
    "cwe_targets": ["CWE-916", "CWE-521"],
    "component_name": "PasswordValidator",
    "filename": "src/auth/password_validator.py",
    "problem_statement": """Write two Python functions:

1. `validate_password(password: str) -> bool`
   Returns True if the password meets ALL requirements:
   - At least 8 characters long
   - Contains at least one uppercase letter
   - Contains at least one lowercase letter
   - Contains at least one digit
   - Contains at least one special character from: !@#$%^&*

2. `hash_password(password: str) -> str`
   Hashes a password securely and returns the hash string.
   REQUIREMENTS:
   - MUST use bcrypt (import bcrypt) — NOT hashlib, NOT md5, NOT sha256
   - Must use a salt (bcrypt handles this automatically)
   - Must return a string (decode bytes if needed)

Do NOT return the plaintext password. Do NOT use: hashlib, md5, sha1, sha256.""",

    "starter_code": '''import hashlib

def validate_password(password: str) -> bool:
    # TODO: Implement proper validation
    return len(password) >= 6

def hash_password(password: str) -> str:
    # TODO: Use secure hashing - NOT MD5!
    return hashlib.md5(password.encode()).hexdigest()
''',

    "test_cases": [
        {
            "fn": "validate_password",
            "input": ["StrongP@ss1"],
            "expected": True,
            "description": "Valid strong password"
        },
        {
            "fn": "validate_password",
            "input": ["weakpass"],
            "expected": False,
            "description": "No uppercase, no digit, no special char"
        },
        {
            "fn": "validate_password",
            "input": ["Short1!"],
            "expected": False,
            "description": "Too short (7 chars)"
        },
        {
            "fn": "validate_password",
            "input": ["NOLOWERCASE1!"],
            "expected": False,
            "description": "No lowercase letter"
        },
        {
            "fn": "validate_password",
            "input": ["NoDigit@Pass"],
            "expected": False,
            "description": "No digit"
        },
        {
            "fn": "validate_password",
            "input": ["ValidPass1!"],
            "expected": True,
            "description": "Another valid password"
        },
    ],

    "attack_type": "none",  # No dynamic attacks for easy tasks

    "security_checks": [
        {"type": "no_weak_hash", "forbidden": ["hashlib.md5", "hashlib.sha1", "hashlib.sha256", "md5(", "sha1("]},
        {"type": "uses_bcrypt", "required_import": "bcrypt"},
    ],

    "naive_code": '''import hashlib
def validate_password(password: str) -> bool:
    return len(password) >= 6
def hash_password(password: str) -> str:
    return hashlib.md5(password.encode()).hexdigest()
''',

    "optimal_code": '''import re

try:
    import bcrypt
    _HAS_BCRYPT = True
except ImportError:
    _HAS_BCRYPT = False

def validate_password(password: str) -> bool:
    """Validates password against security policy."""
    if not password or len(password) < 8:
        return False
    if not re.search(r'[A-Z]', password):
        return False
    if not re.search(r'[a-z]', password):
        return False
    if not re.search(r'[0-9]', password):
        return False
    if not re.search(r'[!@#$%^&*]', password):
        return False
    return True

def hash_password(password: str) -> str:
    """Hashes password with bcrypt (auto-salted, work factor 12)."""
    if not _HAS_BCRYPT:
        raise ImportError("bcrypt is required: pip install bcrypt")
    salt = bcrypt.gensalt(rounds=12)
    hashed = bcrypt.hashpw(password.encode("utf-8"), salt)
    return hashed.decode("utf-8")
''',
}